This project involves the isolation and characterization of those enzymes of Mycobacterium tuberculosis which are capable of altering the biomechanical properties of lung tissue, i.e., a reduction in the forct required to stretch the tissue (alveolar wall) a given length and a decrease in resting tissue length. In vivo these changes would result in a drop in pressure at a given volume and an increase in compliance. These changes ae qualitatively similar to the changes which occur in most patients with chronic obstructive pulmonary disease as well as in many patients with tuberculosis. The long-term goal is to understand the interactions between the mycobacteria and host (host-parasite relationship) which leads to and/or produces the lung damage described above. Studies are in progress to: 1) inceease the yield of activity, 2) determine the nature of the activity, 3) grow sufficient quantities of bacilli to isolate and purify the activity, and 4) characterize the activity. These studies should result in the identification of the active agent(s) as well as suggest a mechanism of action. Thus, the results should broaden our knowledge concerning the pathogenesis of chronic obstructive pulmonary disease.